A Level Biology Practice Exam

What are nucleic acids primarily made from?

1. Amino acids

2. Fatty acids

3. Nucleotides

4. Carbohydrates

The correct answer is: Nucleotides

Nucleic acids, such as DNA and RNA, are primarily composed of nucleotides. Each nucleotide is made up of three components: a phosphate group, a five-carbon sugar (deoxyribose in DNA and ribose in RNA), and a nitrogenous base. The sequence and arrangement of these nucleotides dictate the genetic information carried by nucleic acids, playing a crucial role in the storage and transmission of genetic information in living organisms. The other options do not align with the structure of nucleic acids. Amino acids are the building blocks of proteins, fatty acids are components of lipids, and carbohydrates consist of sugar molecules like glucose. While these biomolecules are essential for various biological functions, they do not contribute directly to the formation of nucleic acids. Thus, the correct answer highlights the fundamental components specific to nucleic acids.